A circuit breaker of the type which utilizes a bimetallic element to open-circuit the device upon detection of an overload generally comprises a fixed contact and a movable contact which are normally closed to complete an electric circuit and a bimetallic element which opens the contacts upon heating in response to an excessive current flow. The device generally comprises means which, after detection of an excessive current flow, maintains the movable contact out of engagement with the fixed contact to prevent undesired closure of the circuit after cooling of the bimetallic element.
In conventional constructions of this type one of the contacts, for example the fixed contact, is generally carried by the bimetallic element while the other contact is carried by a movable member normally retained in a position in which the contacts are closed by the bimetallic element against an elastic force, e.g. the force of a spring.
The deflection of the bimetallic element, as a result of heating by the passage of an excessive current amplitude through an electric circuit, frees the member carrying the movable contact which is thus displaced, by the elastic force, into another position in which the two contacts are spaced apart and the circuit is maintained in an open state until the movable member is manually reset into its original position.
Such constructions, in which the movable contact is carried by a member of the type described above, make it necessary to provide an electrical connection of flexible character, between the movable contact and one of the terminals of the circuit breaker. This is generally disadvantageous when extreme miniaturization of the unit is desired.